Field of the Invention
Embodiments of the invention generally relate to feedthroughs and, more particularly, to feedthroughs suitable for use in high pressure, high temperature, and/or other harsh environments.
Description of the Related Art
Many industries and applications utilize apparatus sensors to measure parameters, such as pressure. In some cases, such sensors may utilize optical waveguides that are designed to penetrate a wall, bulkhead, or other feedthrough member wherein a relatively high fluid differential pressure exists across a feedthrough member. In addition, one or both sides of the feedthrough member may be subjected to relatively high temperatures and other harsh environmental conditions, such as corrosive or volatile gases, liquids, and other materials. For example, a bulkhead feedthrough may call for sealing an optical waveguide at high pressures of about 138,000 kilopascal (kPa) and above, and high temperatures of about 150° C. to 300° C. and above, with a service life of 5 to 20 or more years.
Several challenges exist with constructing a sensor utilizing such an optical fiber feedthrough. One of these problems involves the susceptibility of the glass fiber to damage and breakage due to its small size, flexibility, and brittle nature. Another challenge involves the potential for leaks when the optical fiber is sealed in a feedthrough bore using epoxy or other bonding materials, which may crack when exposed to an extreme range of temperatures and pressures.